|Top view - ELT, Stormscope, COM, GPS and TAS antennas|
I no longer need separate UAT and transponder antennas. Given that Garmin requires a minimum of 3' of cable from the transponder to the antenna, I moved that antenna to the rear part of the tailcone:
|Side view with all antennas|
|Bottom view - transponder, COM, NAV and TAS antennas|
I added a third GPS antenna - one for the GTN, one GPS+XM for the G3X (PFD only), and one for the G5.
|TAS antenna details - ideal and minimum ground plane plus distance to other antennas|
|Distance between the two TAS antennas - this introduces ~0.2˚ bearing error for a 9 or 3 o'clock target at 1sm|
With the transponder antenna moved aft, I'll try using the original XPDR antenna hole for my bottom COM antenna. It's unclear what kind of performance I can get from the ground plane at that location, but since the ground plane area is only about 20% smaller than the top antenna's, I'll just plot the VSWR after the tailcone is attached and see (and if that doesn't work, I'll add another hole in the baggage area and plug this one).
|COM ground plane area is ~1371sqin (ideal is ~1662sqin, ~20% more)|
|Tailcone antenna ground clearance at maximum rotation attitude|
Given that none of these require any structural changes for now (only the top TAS antenna will give me trouble), I'm deferring any installation steps to later when I actually have the avionics - who knows what else may change until then.